Gripping device



' L.l. BERKELEY.

GRIPPING DEVICE.

APPLICATION. FILED AUG-12, I920- 2 II Ii: 33

I 30 Ii I I 2; 1* Q I E L Q K I O WITNESS G v I INVENTOR L. 1. BERKELEY.

{SRIPPING DEVICE.

- ppucn ou HLED. AUG-I2. I 20- Patented May v 2 sssssssss EU 2.

umrno slams "PATENTOFFIQE.

ran'nnncn J. nnnnnnnr, or nacrnn, W'IsoONsIN, ASSIGNOR TD rr RoULns MANU- FACTURING COMPANY. or RAGINE,.WISCONSIN, {A oOnrOnnTIoN or WISCONSIN.

enIIrrrNG Dav es.

Specification OfLetters Patent. Patented j y 23 1922 Application filed' August 12,. 1920. Serial: No. 403,102.

To all whom it may concern:

Be it known. that I. LAUnnNon J; BERKE- LEY, a citizen of the United States, residing at Racine, in the county of Racine and State of Wisconsin, have invented av new and use.

ful Improvement in Gripping Devices. of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming part cf this specificatiom in which- Figure l is a vertical sectional view through one form of my'improved work gripping device.

Figure 2 is a sectional plan view on the line IIII of. Figure 1. y

Figure 3 is a sectional plan viewfillustrating the stationary gripping die, the feed trough and the heading die.

Figure t is a perspective view of the die block.

Figure 5 is a detail vertical sectional view of the movable gripping die holding member.

Figure 6 is a similar view atright angles to Figure 5 and p figure 7 is a perspective view of the wear-- plate for the movable gripping die.

This invention relates to an improvement in gripping dies for forging machines and the like, and is'arranged to provide a die of this character together with its operating mechanism which will positivel hold the workpiece at a fixed position.

Another object of my invention is to pro-v vide operating mechanism for the movable gripping die which is actuated by fluid pressure under control of valve, whereby the actuating mechanism controlled by the movement of the forging press is not placed under undue stresses or strains i Still another object of my invention isto provide means for readily adjusting the controlling mechanism for the valve. so that the time tor Opening and closing the dies can readily be adjusted.

In dies of this character known to me. the gripping dies were closed by means of cams on the forging press and the mechanism was usually provided with yielding means which wouldyield before any of the parts of the press would break if more than one piece of material was fed to the grip By the use OfIllY improved gripping die actuating mechanism I am enabled to exert a predeterminedamount or pressure on the workpiece held between the gripping dies,

irrespective of the size of the workpiece so that there will be no danger oi break ng any of the parts of the machine regardless of the size ot the workpiece fed to the machine.

The precise nature of my invention will be best-understood by reference to the accompanying drawings whlch will now' be described, it being premised, however, that various changes maybe made in the details of construction and general arrangement of the parts without departing from the spirit and scope of my invention as defined in the appended claims. i

In the drawings the reference character 2 designates the main frame or bed plate and 3 a yoke connectin the upper ends of the frame members. Mounted on projections 41 extending inwardly from theirame members 2, is a die block 5, and mounted on this die block 5 is astationary die memberfi which may be adjusted toward and from the center of the machine by means of an adjusting screw 7 having lock nuts 8. Adjustably mounted on the die block 5 at the other side'of the stationary gripping die 6 is a wedge block cam or incline 9 which is also arranged to be adjusted toward and from thestationary gripping die 6 by means of an adjusting screw 10 and is locked in its adjusted position by means of the lock nuts 11 Interposed between an upwardly extending flange 12 on the die block and the members 6 and 9 is a hard steel wear-plate 13. This plate 13 and the flange 12 are provided with recesses 14 in line with the recess in the stationary gripping die 6.. The outer end of the recess l t in the flange 12 is flared outwardly toward the walls of a feed trough 15 through which the blanks 16 are fed to the machine, and 17 is a heading, upsetting or i forging die arranged to upset the end of a workpiece held between the stationary gripping die 6 and the movable gripping die hereinafter described. The yoke 3 provided with a central opening in which is arranged to reciprocate a movable gripping die holder 18 to which is pivotally connected a grip 'iing die support 19 having a wear plate '19 thereonv Removably mounted on the lower end of this die support 19 between shims 20" and a clamp 20 secured to the die support is a movable gripping die 20. The gripping die 20 has a recess 21 at its lower end which is arranged to coact with a recess 22 in the stationary gripping die 6 for holding the workpiece in its proper position with relation to the upsetting or forging die 17. This die is also provided at its lower end with an angular or inclined face 28 which is adapted to coact with the angular or inclined face 24 on the wedge block 9, so that when the die 20 is moi ed downwardly. as hereinafter described, it will be moved laterally by the inclined faces 23 and 24 toward the workpiece. 25 is a spring connected to the die support and the frame 2 for holding the inclined faces 23 and 24: in contact with each other. Mounted on the upper end of the yoke 3 is a cylinder 26, and mounted within said cylinder is a piston having a. large head 27 and a small head 27. The piston is provided with a downwardly extending rod 27 the lower end of which is connected to the gripping die holder 18, so that when said piston is reciprocated the movable die is reciprocated therewith. 28 .is a valve casing having a. valve therein which is provided with a stem 29 extending through one end of the casing, and connected to this stem 29 is a lever 30 for actuating the valve as hereinafter described. 31 is a pressure fluid pipe communicating with this valve casing, which may be connected to any suitable source of pressure supply. 32 is a pipe connecting the upper end of the cylinder 26 above the large head 27 with the valve casing and 553 is a similar pipe connecting the lower end of the cylinder below the head 27 with the ct sing. the arrangement being such that when pressure is admitted above the piston 27 the pipe leading from the lower end of the cylinder will be open to exhaustand when the pipe 33 is open to pressure the pipe 32 will be open to exhaust.

Adjustably mounted in guide 34 is a support and pivotally connected to this support is a crank arm 36. The lower end of the crank arm is provided with a roller 37 arranged to be moved by a cam 38, which cam may be connected to any suitable shaft on the forging press, in such a manner that it maybe readily adjusted to time the operation of said cam with relation to the forging die. The lower end of this crank 36 is connected by means of a link 39 With the lower end of the lever 30 on the valve stem. 40 is a spring connected to the crank 36 and a stationary partof the machinfi for maintaining the roller 37 agai it the cam 38. 4:1. is an adjusting screw for the member which is arranged to adjust the position of said member and with it the pivotal end of the crank arm 36, so that the roller ii" may be adjusted a n'edetermined distance with relation to the cam 38 by shifting the position of the fulcrum point of said crank arm.

The operation of the machine is as follows:

\Vhen a new workpiece is to be fed into the machine, the die members are in the po sition shown in Figure 1, the workpiece to be acted on is pushed from. the trough 15 into the recess 22 in the stationary gripping die 6. Immediately after the workpiece has been placed in position, the cam member 33 will be rotated to permit the spring 40 to actuate the crank arm 36 and through it the lever 30 and admit pressure through the pipe 32 and open the pipe 33 to exhaust. The pressure in the upper end of the cylinder 26 will force the movable gripping die 6 downwardly, and during its downward movement the gripping die will be moved laterally by the face or incline 24; engaging the incline 23 until the. recess therein en gages the workpiece which will securely clamp the workpiece between the recesses 21 and 22. Just before the gripping dies )5 are closed the forging die 17 is advanced to first accurately position the work piece lengthwise relative to said gripping dies and then to perform its operation on the work piece. After the tli'orging'die has perforn'ied its operation the cam 38 will. again shift the valve to reverse the pressure in the pipes 32 and 33 so that the pressure below the piston head 2'? will raise the pisttm.

The advanta es of my invention result from the provision of a plurality of grip-- ping diesfeacl'i of which is arranged to on gage two adjacent tat and one of which is moved to e-rd the other by means of fluid pressure actuated means in adjustably tinieiil relation to the operation of the forging die, to grip the workpiece between the two gripping dies.

The workpieces. such a:- spike bla rs. fol example. which vary more or les in len being fed between the open ping dies: 6 and 20 towards the for ng 7 projecting beyond the greater extentthan proper operation of the for are thrust back by the to to position to leave the exact stock projecting from the gripping; dies for the required upsetting, bending or other opera tion of the forging die, whereupon the grip- 1. ping dies are instantly closed upon the workpieces or blanks by fluid pressure :uljustably controlled by the operation of a part of the machine in exact timed relation to the work ing stroke of the forging die.

By the use of fluid actuated. means for moving the die members relative to each other, I am enabled to apply a predetermined amount of pressure to the gripping dies, regardless ot the gauge of material fed to the dies and am also enabled to provide means for controlling the movement of the one die member which can be readily and quickly operated with a very small amount of power from the forging machine, whereby I overcome the excessive hammering of this part of the mechanism and also the tendency for moving the actuating mechanism out of: its adjusted position which is caused by the excessive shock on the cams when closing the dies.

I claim:

1. A device of the character described, comprising a plurality of gripping dies, an operable forging die cooperating therewith, fluid pressure actuated means for moving one of the gripping'dies relative to the other, and means controlling said fluid pressure actuated means in timed relation to the oper ation of the forging die, substantially as described.

2. A device of the character described, comprising a plurality of gripping dies, an operable forging die cooperating therewith, fluid pressure actuated means for moving one of the gripping dies relative to the other, and a valve operable in timed relation to the operation of the forging die for controlling said pressure actuated means, substantially as described.

3. A device of the character described, comprising a plurality of gripping dies, an operable forging die cooperating therewith, a cylinder, a piston within. said cylinder connected to one of said gripping dies and valve mechanism operable in timed relation to the operation of the forging die for con trolling the admission of fluid to and ex haust fluid from said cylinder, substantially as described.

4;. A device of the character described, comprising a plurality of gripping dies. a cylinder, a piston within said cylinder connected to one of said dies, adjustable valve mechanism for controlling the admission and release of fluid to and from said cylinder, and varying the time of closing the gripping dies, substantially as described.

5. A device of the character described, comprising a stationary gripping die, movable gripping die extending at an angle thereto, and fluid pressure means for moving said movable gripping die "into and out of cooperative engagement with said fixed die to grip an article between said dies or release the same, substantially as described.

6. A device of the character described, comprising a stationary gripping die, a movable ripping die extending at an angle thereto, fluid pressure means for moving said movable grippingdie in one direction,

and means independently thereof for moving said movable gripping die in a direction at substantially right angles to said first mentioned direction and. in line with said stationary gripping die, substantially as described.

7. A device of the character described, comprising a stationary gripping die, a movable gripping die extending at an angle thereto, fluid pressure means for moving said griping die into and out of cooperative engagement with said fixed die to grip an "article between said dies, and means for adjusting said stationary gripping die, substantially as described.

8. A device of the character described, comprising gripping dies one of which is movable towards and from the other, fluid pressure actuated means for operating the movable gripping die, a forging die movable towards and from the gripping dies, and means connected with the forging die operating means and adapted to admit fluid pressure to the gripping die operating means at a predetermined point in the working stroke ofthe forging die, substantially as described.

9. In a forging machine the combination of gripping dies one of which is movable towards and from the other, fluid pressure actuated means for operating the movable gripping die, a forging die movable towards and from the gripping dies, adjustable means actuated in timed relation to the forging die for controlling the admission of fluid pressure to the gripping die operating means whereby the forging die first positions a. work piece lengthwise between the gripping dies and then at a predetermined point in its working stroke the gripping dies are closed upon and firmly grip the work piece while the forging die performs its operation thereon. substantially as described.

10. A device of the character described, comprising a stationary gripping die, a movable gripping die extending at an angle thereto, fluid pressure means for moving said movable gripping die in one direction, means independently thereof for moving said movable gripping die in direction at substantially right angles to said first named direction and in line with said stationary gripping die, and means for adjusting said stationary die and said last named means, substantially as described.

11. A- device of the character described, comprising a sectional gripping die and a forging die, means for moving one of said. dies relative to the other, fluid pressure actuated means for actuating a section of said gripping die, and means controlling said fluid pressure actuated means in timed relation with the movements of the movable die, substantially as described.

12. A device of the character r loseribed, comprising a, stationary die and adie mov able with relation to said stationary die, one of said dies being 2L sectional gripping die, fluid pressure actuated niemiie for zn'tua ting a. section of said gripping die, and means controlling said fluid pressure actuated means in timed relation. with the moven'iente of the movable die, substantially as described. i 0

In. testimony whereof, I have hereunto set my hand. 

